Mechanical time fuse



April 11, 1939. H. JUNGHANS MECHANICAL TIME FUSE Filed July 24, 1937 Jaye/7M1: Wm

Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE Application July 24, 1937, Serial No. 155,445 In Germany May 17, 1935 3 Claims.

This invention relates to a mechanical time fuse which is sensitive to impact, and of which its mechanism is substantially identical to that described in my Patent No. 2,011,286. The characteristic features of the invention disclosed therein were a device for delayed action containing a clockwork mechanism with balance disposed centrally in the fuse, and with a sensitive impact device having a common locking element which is capable of being released singly by either method of ignition.

The locking element is constructed in the form of a shaft having an arm which isadapted to enter a corresponding slot in the time disc and to release the firing element by reason of the rotating disk. The shaft is also mounted in a special bearing which can be displaced by the downwardly moving percussion pin, in such fashion that the firing element is released from the lock ing member. In order to maintain the movable bearing in the position of rest there is employed a spring-controlled member which is actuated by the downwardly moving I percussion pin. The bearing is thus able to move under the action of the centrifugal force, for a release of the firing element.

The purpose of my invention is to provide a time fuse substantially identical to that described in my Patent No. 2,011,286 but wherein the impact device is of increased sensitivity. To accomplish this object the invention provides means for making the resiliency of the notch lever,-

which is actuated by the percussion pin upon the downward movement, of a more elastic nature. This enhanced resiliency is made up in part of the natural resiliency of the said lever and in part of the adjustable spring force of a springpressed bolt engaging with the notch lever.

By means of this arrangement it is possible to not alone increase the resiliency of the notch lever, but to also make it readily adjustable. It is impossible to reduce the spring force of the notch lever below a certain amount for the reason that as the eiTect of the centrifugal force on the resilient notch lever would impair the action of the lever and render the same less reliable. To preclude this effect of the, centrifugal force it might appear natural to reinforce the resilient portion of the notch lever. This method, ho ever, is unsuitable owing to the fact that in this way the resiliency would become hard and delay the action. It is only by the co-operation of two elastic agents that the force maintaining the notch connection can be increased whilst upholding or increasing the elasticity of the device.

An embodiment of the invention is illustrated by way of example in the accompanying drawing, in which i I Fig. 1 is a plan view of a fuse plate with the hook arrangement and the spring-pressed bolt engaging with the hook, in the locked position.

Fig. 2 is a cross-section of the embodiment shown to Fig. 1, there also being shown parts of the operating and releasing mechanism.

Figs. 3 and 4 show the hook arrangement corresponding to Figs. 1 and 2 in the position of release.

To facilitate an understanding of my present invention I will give a short description of the principal structural features of the time according to my Patent No. 2,011,286.

The central shaft IQ of the clockwork, on which is mounted the adjustment disc 20, is bored throughout its entire length. In this bore is guided the percussion bolt II which, upon impact of the projectile against any resistance, is pressed down. In order that this movement may not take place at the firing, a safety tube lying above the mechanism, but not shown, is provided for the percussion bolt l I.

When'the fuse is set for retarded ignition, the engaging lever 2| securely connected with the shaft 5 slides in the known manner with its bentup end (not shown) on the circumference of the adjustment disc 20 driven by .the mechanism, until the bent up end falls into the aperture 20a of this disc, whereby the shaft 5 is subjected to a slight rotation, owing to which a lever I8 is able to enter the milled out recess 5a of the shaft 5, which brings about the engagement of the ignition device of any desired form, which is not shown.

An immediate release of the lever l8 takes place upon the impact owing to the fact that the shaft in that its bearings, or only one of them, are enabled to shift outwardly by centrifugal force.

For this purpose in the plate I there is provided a recess I acting as guide for the radially shiftable bearing bridge 3. The bearing bridge 3 possesses at its outer end a bore 4 for accommodation of the locking member 5, which is constructed in the form of a shaft or bolt. At the inner end the bridge 3 possesses an upwardly directed projection 6 engaging with a spring hook 8 which is screwed firmly to the plate at 9. On the front end of the hook there is fitted a conical member I which by means of its inclined surface co-operates with the percussion pin ll having the corresponding conical point, in such fashfuse l V proximately central position of the resilient portion of the hook this part is acted upon to a slight extent by centrifugal force. In order now to increase the spring effect and also the elasticity oi the device there is provided a springpressed bolt l2 accommodated in a corresponding by the spring the upwardly bent lug tained the nature of said invention,

boring E3 in the upper plate It and acted upon it, for the setting of which there is provided the screw it closing the boring at the end. The spring-pressed bolt l2 engages'with ll of the hook ii-and opposes the opening of the hook connection.

By reason of the centrifugal force the action of the pressure bolt is again in part overcome. The force of the pressure spring should, there fore, be selected accordingly. It will be obvious that the safety means as described also ofiers advantage when the fuse is subjected to jolts or the like during transport, as it will oppose any undesired opening of the hooir connection.

The operation of the fuse is as iollovvs:--

In case oj time ignition the arm on the shaft 'or bolt 5 enters a slot in the time disc in the known fashion. Owing to the rotation of the shaft or bolt thus caused the firing element 88 is released.- in case of impact ignition the hook connection with the bridge 3 is released by the percussion pin and the bridge 3 is moved outwardly whereby, the shaft or bolt 5 is caused to assume an inclined position, so that also in this case the firing element it is released.

Having now particularly described and ascerand in area-we what manner the same isto be performed, 5 declare that what I claim is:-

1. In a mechanical time fuse the combination with firing control means, of a shiitable' element controlling said means, a resilient lock lever adapted for locking and releasing said shiftable element, a movable bolt engaging said. lock lever, a spring behind said bolt for causing a pressure on said lever, means for adjusting the pressure of said spring and a percussion pin ionreleasing said lock lever against the combined resilient forces of said lever and spring.

2. In a mechanical time fuse the combination with firing control means, of a shiftabie element controlling said means, a resilient lock lever of substantially soit resiliency adapted for locking and releasing said shiitable element, 9.. lug ex tending from said lever, a movable bolt engaging said lug, a spring behind said bolt for calming a pressure on said lever, means for adjusting the pressure of said spring and a percussion pin for releasing said lock lever against the combined re= silient forces of said lever and spring.

3. In a rotated mechanical time iuse the coin ,bi'nation with firing control means of a resilient lock lever for controlling said means, a spring element operatively engaging said loch lever and a percussion pin for releasing said lock lever against the combined resilient forces of said lever and spring, the sum of the resilient forces of both said spring lever being greater acting on said lever iuse than the centrifugal force due to the rotation of said M :n GHAKS.

element and said lock. 

